and my evolution to PSI. I mean, I would say to Stefano, when I was a resident, I saw Stefano as one of his professors, Murillo Marcacci, and I saw him do a femoral tibial tubercle osteotomy in 45 minutes. And it was that day, and I saw a lot of knee replacement HSS, but that was the sentinel moment for me where I was like, wow, that's a master surgeon? And he was, it totally opened my eyes. And that hall, if you ever have a chance, go to Bologna, it's a fantastic place. You'll see Puru's original ashtray. It's an amazing place, it's totally, and I had a great time, and then Professor Marcacci would be like, Anil, how many more patients? I go, two. He'd go, let's go get a glass of wine. I'm like, what, Murillo Clinic? But that was Marcacci, he was amazing. So let's talk about PSI, why I love osteotomy, meal opening wedge, my indications, techniques, and my evolution to PSI. Well, Stefano talked about this, I love osteotomy because at HSS in the late 90s, osteotomy was killed because they thought tone knees could solve all the problems, but it really can't. An osteotomy can help you with PCL and ACL deficient knee, can help collateral surgery. Once you have an osteotomy, I let patients do anything. It can truly be disease modifying. I don't think it's replacing a knee replacement, it's a different indication, and it always makes, for all the fake cartilage surgeries out there, it makes me a bad cartilage surgeon much better because once you unload the joint, it can really help your bad cartilage procedure. I really feel that there has been a renaissance because there was a shift of early arthroplasty. The arthroplasty guys got burned, you know, they did early intervention, and now they're like, oh, there's good science now. We shouldn't do an arthroplasty on a grade two, grade three, early arthritic knee, and osteotomy's making a comeback. The historic data hasn't always been great, but it's been historic data. A lot of this is closing wedge. A lot of this was done for advanced disease, too. So you gotta think, when you look critically at the data, look about it, you know, it's a closing wedge osteotomy, and it's also done for more advanced disease. The earlier we intervene, the better. The more we address the deformity in all planes, the better, and that's really what we're hearing, and Al, I'm sure, will talk about that. But, you know, this is what's wrong with HGO. I always tell my residents and fellows, if you break someone's leg, you better make sure it heals. It's really bad. You broke it. So what's the problem with HGO? Immobilization, nonunion, lateral side overload, inaccurate correction, Baha, knee pain. I think a lot of these are closing wedge issues, but a lot of them are opening wedge issues as well. Why I like opening wedge, it's better outcomes, better function, I think it's more knee hematics. Why I like it, it's bone restoring. It's improving proximal tibia vera. I think I'm going after that early blounced knee, and I wanna reduce that tibia parallel to the joint line. That's my goal. I'm restoring bone, if they ever do knee otomy, and the conversion to otomy is much quicker. And as we can see, you know, opening wedge is getting better than closing wedge at the 10-year mark. It's also, I think, has better control of multiple planes. A closing wedge osteotomy, to Volcker's point, is a much harder osteotomy, because there's two cuts, and you can easily get your wedge off. I think an opening wedge is an easier osteotomy. Slope manipulation, I think closing wedge is actually better in this scenario, because closing wedge, you can more reproducibly take away slope, but with advanced technology, I'm gonna show you that I think we can actually reduce slope, even with an opening wedge. I also think an opening wedge is better for patella kinematics, and we talked about ease of conversion. Clearly, an opening wedge is better. So, although there's a lot of controversy here, I ultimately believe there's a role for both. It's not one versus the other. Whenever you have an osteotomy versus uni, or opening versus closing, it's all about indications. Pick the right indications, and you should have these both in your arm interior. So again, my indications for an opening wedge, I really wanna go for proximal tibia vera. I'm half Indian, I go to India a lot, and they have a congenital deformity of their proximal tibia. They're in a lot more verus, and there's a lot of osteotomies done in India, and that's the knee I wanna go for. I don't like flexion contractures when I do osteotomies. Sometimes, when I have large deformities, I have no problem giving this to my frame colleagues and do a frame, and then what's my technique? This is my traditional AO technique, my tomofix technique, where I do a medial incision, I release the MCL, I release the pes, I do a big flap, I put in laminar spreaders, I do a gradual distraction, let the bone breathe, I let the hinge breathe, I get proximal fixation, and then I hyperextend the knee to make sure my slope and my gap is one to two ratio, and I do early weight bearing. So here's quickly some videos. Again, I always wanna assess if there's correctability of their verus. I'm a ranawat, we do big incisions, okay? Small incisions are for smaller surgeons. I do a big MCL release, and I don't cut the MCL, but I go very distal, I get to the posterior compartment, and in the very beginning of your career, take your finger, go all the way around the back of the knee and touch that fibula. Get confidence that you can get in the back of the knee. And then also, you wanna release the tubercle as well. Then you put your pins across, I measure my cut. Here's the thing where I wanna say, we're gonna see with PSIs better, that's looking at a biplanar cut. I will do heavy irrigation. Saws is what prevents bone to heal. So understanding your thermonecrosis is probably the biggest indication of how you can get good healing of an opening wedge osteotomy. And then this is the classic Mayo technique. When I put these osteotomes, I make the residents say, hoop stress, hoop stress, hoop stress, you gotta let the bone breathe, okay? And this is something that you wanna just take a little bit of time, and then you do a distraction device, and then you open the osteotomy, and then you get proximal fixation, and then I hyperextend the leg, and I overcorrect the osteotomy, and then I do a lag technique, so I have a tension bag technique. This is AO101, so if I have a 10 degree correction, I can do 11, I compress it back to a 10, and I have my bone graft in there. So that's how you get good bony healing. And then I always assess my gap, and I'm looking at my one to two ratio. I think the lost art of an opening wedge osteotomy is balancing the knee. So I have no problem piecresting the MCL, piecresting the posterior oblique ligament, if I still have some tightness in my knee. If you do a, there's been a paper by Philip Lobenhofer, if you do a valgus osteotomy and the MCL's too tight, it actually doesn't help your compartmental pressures as much as you think it does. So if you understand the varus knee, whether it's a uni, toe knee, or osteotomy, it has to be soft tissue balancing too. Like any operation in the knee, it's not just a bony operation. So we've conquered osteotomy, we're all done, right? No, because if you were at my ICL, Volcker, it was all about complications, and I talked about a lot of complications, and there are a lot of complications. I mean, there's certain complications we can accept, removal of hardware, perineal nerve, hinge fracture, reoperation, those are complications we can't accept, and I really think you gotta separate those two, because that's what you really wanna go after. So how did I get to PSI? Well, I really think it's a way to minimize complications. It's advanced digital templating for an accurate correction, because really, the goal of this operation is an accurate correction. It's giving safety. What I wanna do for osteotomy is what my father did for toe knee. I wanna make this an average surgeon's operation. I am no Murillo Marcocci. He took no fluoro. I would've probably taken 15 fluoro shots for a femur, tibia, and tubercle. I mean, it was crazy. So I need some help, and I think everyone needs some help, because we wanna afford safety to the patient. We also want procedural workflow and efficiency, and lastly, we wanna expand the horizon. When we were here eight years ago, no one talked about slope. No one talked about osteotomy. Slope, you can't go into a room if you don't hear about slope and osteotomy. So this is really expanding the indications of the procedure. So this is what it does. It incorporates a long leg cassette with a CT scan, so you functionally get a weight-bearing CT scan. If you look at the MAKO protocol, they don't do this. They just have a CAT scan. So this overlap really gets some concepts of soft tissue balancing, and you'll see lateral side opening, and we can talk about joint line congruity angle. That's a lot of interesting stuff. Then I do my virtual osteotomy. This is digital templating. Even if you don't believe in PSI, even if you don't believe in a patient-specific plate, that's all fancy American HSS, you rich guys, you guys do all these things you don't need to do. Digital templating is the way to go, and you can do a single level, double level. I can do a tubercle, whatever. I can do a closing wedge. Whatever osteotomy I think is right, I can play with it on this digital templating system. And also, I have all the procedural osteotomy angle parameters on the side. Then you have a patient-specific jig that fits like a glove. Placing this jig properly is the operation, and then you have a simple workflow, and it's using not a saw, but drill bits. There are saw techniques, and there are drill bit techniques. I love drill bits because it doesn't cook the bone, and my osteotomy healing rates are much faster, and my ability to weight-bear them is much faster, and it's much less fluoro time, because once I put this jig on, I take one x-ray to spot it, I know it's gonna be spot on. And the last thing, it just increases your efficiency. So this is a hard, a little stressful operation. I think there were a lot of bad osteotomies done fast. I don't wanna beat up Freddie, because he was my mentor, and I loved him. But fast with osteotomy isn't always right, because you wanna be accurate, and this can give you speed and accuracy. So these are some things that we've figured out in terms of versatility and slope, that we found that if you do an anterior lateral hinge, you destabilize the posterior lateral cortex. It's really the only way with an opening-edge osteotomy, you can reduce your slope. So understanding hinge axis has completely exploded the concept of opening-edge osteotomy for both, for an ACL-deficient knee, and obviously you can do a bad osteotomy for a PCL-deficient knee by increasing slope. So quickly, just a case. This is a medial meniscectomy knee. I was always thinking, you know, where should I put it in? But this is my favorite patient. He's an engineer. Now, when you have an engineer, and you say, your car is mal-aligned, and your tire is running thin. Like, they just say, oh, that makes total sense. When you have an investment banker, they're like, they walk out of the room. So those are my favorite patients. They understand osteotomy. This is a lab case, this guy 15 years ago. I put him to the lateral spine, and he's still doing great. Here's a more complex one. This is a 37-year-old. She's varus alignment, increased tibial slope, failed three ACLs, and I wanted, she was in more pain than instability. So I did, she was about 20 degrees of slope. So I did a PSI, and I did a slope correction. You can see that posterior lateral tibia is really destabilized. So you actually get a cut with a saw, or an osteotome, through your hinge. And it's disconcerting, but your anterior lateral hinge is still intact. So I preoperatively planned this. I took out her slope, took out her varus, never did her ACL. She's now five years out, and she loves this knee. If you correct the alignment, you can get away with a lot of ligamentous instability. So in conclusion, I think Miele Open Image Osteotomy is highly versatile. It's biomechanically sound. It's bone-preserving. PSI will teach you your mistakes, and make you a better and safer surgeon. Thank you very much. Thank you. Thank you. Thanks, Anil. That was brilliant. You know, I think with the PSI, we all have a lot to learn. I wonder if PSI is like many of the technologies where you have now learned how to do preoperative planning really efficiently. I mean, that's perfect. It's beautiful. Is your learning curve already reached after like five or 10, and you want more? Like, what's the next step in this? Yeah, I mean, I definitely, I mean, with any new technology, my first five or 10 PSIs took me longer, right? And I had bigger incisions. I was faster with the tomofix. So, and I also, I realized how I was consistently under-correcting because I wasn't really taking account my saw thickness into my corrections. And with the CT scan, they can really get the saw thickness, you know, to a much higher degree. So I actually under-correct a little bit now with the PSI. So you learn all the different tools. I'd say it takes about 10 or 20 cases, but it's a type of thing. Larry Doerr, a famous total hip surgeon, who's the father of total hip navigation, said to me, when you do PSI, or you do navigational robotics, it teaches you your errors, and you don't realize how many of your errors that you've had, and you thought you were on, and you weren't. And that's why I think it's a powerful tool. That's awesome. Thank you. All right, next.

Dr. Anil Ranawat

osteotomy benefits

patient-specific instrumentation

soft tissue balancing

PSI advantages